442 BOTANICAL GAZETTE [DECEMBER 
structure and apparently of less interest. Iam not in the position to 
draw any anatomical comparison, therefore, between the species from 
the Rocky Mountains and those from other alpine regions. The 
alpine types which have been treated and studied in Europe are nearly 
all dicotyledons, and the results are not quite comparable to those 
derived from the study of our Gramineae. According to BONNIER" 
and WaGNER,"® the palisade tissue should be far better developed in 
the alpine forms (dicotyledons) than in those from the lowlands; the 
leaves should be thicker, and the structure more open on account of 
the wider intercellular spaces; also the alpine leaves should be more 
thoroughly dorsiventral, with stomata sometimes more abundant on the 
ventral than on the dorsal face; the guard cells should be level with 
the epidermis except in species with evergreen leaves (Ericaceae, etc.). 
These distinctions are not to be observed in the Gramineae. We 
have seen that in the alpine representatives of this family the leaves 
are not dorsiventral; the palisade tissue is not developed to any greater 
extent than in the lowland species; the chlorenchyma is not open, 07 
the contrary it is very compact; also the stomata are not level with 
the epidermis but mostly sunken. It seems almost safe to conclude that 
the epharmonic characters are much less pronounced in the alpine 
Gramineae than in the dicotyledons from similar high situations, when 
compared with the corresponding lowland types. Much would be 
learned, however, by examining alpine Gramineae from other parts 
of the world, and especially other genera and species than those 
described in the preceding pages. Also the study of alpine types 
ought not to be restricted to a mere consideration of the foliar organs, 
even if these unquestionably are the most important; the structure © 
stem and root ought not to be excluded altogether, as is frequently oF 
nearly always the case. 
Conclusions 
We have seen that the alpine Gramineae of Colorado aril 2 
an assemblage of very distinct geographical types; some that are onty 
7 mpt. 
15 BONNIER, Gaston, Cultures expérimentales dans les hautes altitudes. é re 
Rend. Acad. Sci. 1890; Etude expérimentale sur l’influence du climat alpin 
végétation et les fonctions des plantes. Bull. Soc. Bot. France 1888 : 436- 
*© WAGNER, Zur Kenntniss des Blattbaues der Alpenpflanzen = 
biologischer Bedeutung. Sitgungsber. K. Akad. Wiss. Wien 101:59- 189? 
